Three different manufacturers filled the top three places at the end of the first MotoGP practice session of 2012, and the new 1000cc era, led by Honda's reigning double champion Casey Stoner in Qatar on Thursday evening.

Having topped all three pre-season tests, few would be surprised to see Stoner on top of the timesheets. However much of the 45-minutes session was dominated by Yamahas, with factory team-mates Jorge Lorenzo and Ben Spies, plus Tech 3's Cal Crutchlow all setting the pace with the much more competitive 1000cc M1.

But it wasn't enough to prevent Stoner bumping former world champion Lorenzo, riding in his first grand prix since losing part of a finger in a warm-up fall at Phillip Island last October, from the top by 0.174sec on his penultimate lap.

Moments earlier, Ducati's Nicky Hayden - who missed much of pre-season testing due to injury - slotted in behind Lorenzo and the American's early third (+0.450sec) marks an encouraging start to the weekend for the all-new aluminum-frame GP12.

Countryman Spies was demoted to fourth by Hayden's late lap, while Stoner's team-mate Dani Pedrosa moved up to fifth on his final circulation (+0.656sec) after languishing at the lower end of the top ten for much of the session.

Crutchlow confirmed his testing form to be the top satellite rider (+0.921sec), but was just a fraction ahead of new Gresini Honda rider Alvaro Bautista, who broke his femur during practice for Qatar last year.

New Tech 3 signing Andrea Dovizioso clocked the eighth best time with Hector Barbera the second-best Desmosedici in ninth for Pramac. Factory Ducati star Valentino Rossi was left down in tenth place, 1.440sec from Stoner and one-second behind team-mate Hayden.

Karel Abraham (Cardion AB Ducati) and rookie Stefan Bradl (LCR Honda) rounded out the twelve manufacturer entries, with Randy de Puniet and Colin Edwards then leading the new CRT challenge.

Aspar ART rider de Puniet wasn't able to get as close to the manufacturer bikes as in the Jerez test, lacking one-second to Bradl, but Edwards - who struggled at the final test - made a sudden leap in performance on his last lap of the evening with the Suter-BMW.

de Puniet was 3.5sec behind Stoner and 20.5km/h slower than the Australian in terms of top speed. The fastest bike on track was Barbera, 3km/h ahead of Stoner at 337.2km/h. The slowest was the CRT Ioda-Aprilia of Danilo Petrucci, at 288km/h.

The second and third MotoGP free practice sessions will take place on Friday evening.

With no prior 2012 testing at Qatar, the order could change significantly on day two.

Thursday free practice:

1. Stoner
2. Lorenzo
3. Hayden
4. Spies
5. Pedrosa
6. Crutchlow
7. Bautista
8. Dovizioso
9. Barbera
10. Rossi
11. Abraham
12. Bradl
13. de Puniet
14. Edwards
15. Pirro
16. Espargaro
17. Silva
18. Pasini
19. Hernandez
20. Petrucci
21. Ellison